lockd: Start PF_INET6 listener only if IPv6 support is available

Apparently a lot of people need to disable IPv6 completely on their distributor-built systems, which have CONFIG_IPV6_MODULE enabled at build time. They do this by blacklisting the ipv6.ko module. This causes the creation of the lockd service listener to fail if CONFIG_IPV6_MODULE is set, but the module cannot be loaded. Now that the kernel's PF_INET6 RPC listeners are completely separate from PF_INET listeners, we can always start PF_INET. Then lockd can try to start PF_INET6, but it isn't required to be available. Note this has the added benefit that NLM callbacks from AF_INET6 servers will never come from AF_INET remotes. We no longer have to worry about matching mapped IPv4 addresses to AF_INET when comparing addresses. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

lockd: Start PF_INET6 listener only if IPv6 support is available
Apparently a lot of people need to disable IPv6 completely on their distributor-built systems, which have CONFIG_IPV6_MODULE enabled at build time. They do this by blacklisting the ipv6.ko module. This causes the creation of the lockd service listener to fail if CONFIG_IPV6_MODULE is set, but the module cannot be loaded. Now that the kernel's PF_INET6 RPC listeners are completely separate from PF_INET listeners, we can always start PF_INET. Then lockd can try to start PF_INET6, but it isn't required to be available. Note this has the added benefit that NLM callbacks from AF_INET6 servers will never come from AF_INET remotes. We no longer have to worry about matching mapped IPv4 addresses to AF_INET when comparing addresses. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever · Trond Myklebust
1 parent 9355982830
Showing 2 changed files with 22 additions and 59 deletions Side-by-side Diff
fs/lockd/clntlock.c
fs/lockd/svc.c
@@ -139,56 +139,7 @@
 	return 0;
 }
  
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-static const struct in6_addr *nlmclnt_map_v4addr(const struct sockaddr *sap,
-						 struct in6_addr *addr_mapped)
-{
-	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
-
-	switch (sap->sa_family) {
-	case AF_INET6:
-		return &((const struct sockaddr_in6 *)sap)->sin6_addr;
-	case AF_INET:
-		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, addr_mapped);
-		return addr_mapped;
-	}
-
-	return NULL;
-}
-
 /*
- * If lockd is using a PF_INET6 listener, all incoming requests appear
- * to come from AF_INET6 remotes.  The address of AF_INET remotes are
- * mapped to AF_INET6 automatically by the network layer.  In case the
- * user passed an AF_INET server address at mount time, ensure both
- * addresses are AF_INET6 before comparing them.
- */
-static int nlmclnt_cmp_addr(const struct nlm_host *host,
-			    const struct sockaddr *sap)
-{
-	const struct in6_addr *addr1;
-	const struct in6_addr *addr2;
-	struct in6_addr addr1_mapped;
-	struct in6_addr addr2_mapped;
-
-	addr1 = nlmclnt_map_v4addr(nlm_addr(host), &addr1_mapped);
-	if (likely(addr1 != NULL)) {
-		addr2 = nlmclnt_map_v4addr(sap, &addr2_mapped);
-		if (likely(addr2 != NULL))
-			return ipv6_addr_equal(addr1, addr2);
-	}
-
-	return 0;
-}
-#else	/* !(CONFIG_IPV6 || CONFIG_IPV6_MODULE) */
-static int nlmclnt_cmp_addr(const struct nlm_host *host,
-			    const struct sockaddr *sap)
-{
-	return nlm_cmp_addr(nlm_addr(host), sap);
-}
-#endif	/* !(CONFIG_IPV6 || CONFIG_IPV6_MODULE) */
-
-/*
  * The server lockd has called us back to tell us the lock was granted
  */
 __be32 nlmclnt_grant(const struct sockaddr *addr, const struct nlm_lock *lock)
@@ -215,7 +166,7 @@
 		 */
 		if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
 			continue;
-		if (!nlmclnt_cmp_addr(block->b_host, addr))
+		if (!nlm_cmp_addr(nlm_addr(block->b_host), addr))
 			continue;
 		if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0)
 			continue;
@@ -193,20 +193,30 @@
 	return 0;
 }
  
-static int create_lockd_listener(struct svc_serv *serv, char *name,
-				 unsigned short port)
+static int create_lockd_listener(struct svc_serv *serv, const char *name,
+				 const int family, const unsigned short port)
 {
 	struct svc_xprt *xprt;
  
-	xprt = svc_find_xprt(serv, name, 0, 0);
+	xprt = svc_find_xprt(serv, name, family, 0);
 	if (xprt == NULL)
-		return svc_create_xprt(serv, name, PF_INET,
-					port, SVC_SOCK_DEFAULTS);
-
+		return svc_create_xprt(serv, name, family, port,
+						SVC_SOCK_DEFAULTS);
 	svc_xprt_put(xprt);
 	return 0;
 }
  
+static int create_lockd_family(struct svc_serv *serv, const int family)
+{
+	int err;
+
+	err = create_lockd_listener(serv, "udp", family, nlm_udpport);
+	if (err < 0)
+		return err;
+
+	return create_lockd_listener(serv, "tcp", family, nlm_tcpport);
+}
+
 /*
  * Ensure there are active UDP and TCP listeners for lockd.
  *
  
  
@@ -222,13 +232,15 @@
 	static int warned;
 	int err;
  
-	err = create_lockd_listener(serv, "udp", nlm_udpport);
+	err = create_lockd_family(serv, PF_INET);
 	if (err < 0)
 		goto out_err;
  
-	err = create_lockd_listener(serv, "tcp", nlm_tcpport);
-	if (err < 0)
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	err = create_lockd_family(serv, PF_INET6);
+	if (err < 0 && err != -EAFNOSUPPORT)
 		goto out_err;
+#endif	/* CONFIG_IPV6 || CONFIG_IPV6_MODULE */
  
 	warned = 0;
 	return 0;
...	...	@@ -139,56 +139,7 @@
139	139	return 0;
140	140	}
141	141
142		-#if defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE)
143		-static const struct in6_addr nlmclnt_map_v4addr(const struct sockaddr sap,
144		- struct in6_addr *addr_mapped)
145		-{
146		- const struct sockaddr_in sin = (const struct sockaddr_in )sap;
147		-
148		- switch (sap->sa_family) {
149		- case AF_INET6:
150		- return &((const struct sockaddr_in6 *)sap)->sin6_addr;
151		- case AF_INET:
152		- ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, addr_mapped);
153		- return addr_mapped;
154		- }
155		-
156		- return NULL;
157		-}
158		-
159	142	/*
160		- * If lockd is using a PF_INET6 listener, all incoming requests appear
161		- * to come from AF_INET6 remotes. The address of AF_INET remotes are
162		- * mapped to AF_INET6 automatically by the network layer. In case the
163		- * user passed an AF_INET server address at mount time, ensure both
164		- * addresses are AF_INET6 before comparing them.
165		- */
166		-static int nlmclnt_cmp_addr(const struct nlm_host *host,
167		- const struct sockaddr *sap)
168		-{
169		- const struct in6_addr *addr1;
170		- const struct in6_addr *addr2;
171		- struct in6_addr addr1_mapped;
172		- struct in6_addr addr2_mapped;
173		-
174		- addr1 = nlmclnt_map_v4addr(nlm_addr(host), &addr1_mapped);
175		- if (likely(addr1 != NULL)) {
176		- addr2 = nlmclnt_map_v4addr(sap, &addr2_mapped);
177		- if (likely(addr2 != NULL))
178		- return ipv6_addr_equal(addr1, addr2);
179		- }
180		-
181		- return 0;
182		-}
183		-#else /* !(CONFIG_IPV6 \|\| CONFIG_IPV6_MODULE) */
184		-static int nlmclnt_cmp_addr(const struct nlm_host *host,
185		- const struct sockaddr *sap)
186		-{
187		- return nlm_cmp_addr(nlm_addr(host), sap);
188		-}
189		-#endif /* !(CONFIG_IPV6 \|\| CONFIG_IPV6_MODULE) */
190		-
191		-/*
192	143	* The server lockd has called us back to tell us the lock was granted
193	144	*/
194	145	__be32 nlmclnt_grant(const struct sockaddr addr, const struct nlm_lock lock)
...	...	@@ -215,7 +166,7 @@
215	166	*/
216	167	if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
217	168	continue;
218		- if (!nlmclnt_cmp_addr(block->b_host, addr))
	169	+ if (!nlm_cmp_addr(nlm_addr(block->b_host), addr))
219	170	continue;
220	171	if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0)
221	172	continue;
...	...	@@ -193,20 +193,30 @@
193	193	return 0;
194	194	}
195	195
196		-static int create_lockd_listener(struct svc_serv serv, char name,
197		- unsigned short port)
	196	+static int create_lockd_listener(struct svc_serv serv, const char name,
	197	+ const int family, const unsigned short port)
198	198	{
199	199	struct svc_xprt *xprt;
200	200
201		- xprt = svc_find_xprt(serv, name, 0, 0);
	201	+ xprt = svc_find_xprt(serv, name, family, 0);
202	202	if (xprt == NULL)
203		- return svc_create_xprt(serv, name, PF_INET,
204		- port, SVC_SOCK_DEFAULTS);
205		-
	203	+ return svc_create_xprt(serv, name, family, port,
	204	+ SVC_SOCK_DEFAULTS);
206	205	svc_xprt_put(xprt);
207	206	return 0;
208	207	}
209	208
	209	+static int create_lockd_family(struct svc_serv *serv, const int family)
	210	+{
	211	+ int err;
	212	+
	213	+ err = create_lockd_listener(serv, "udp", family, nlm_udpport);
	214	+ if (err < 0)
	215	+ return err;
	216	+
	217	+ return create_lockd_listener(serv, "tcp", family, nlm_tcpport);
	218	+}
	219	+
210	220	/*
211	221	* Ensure there are active UDP and TCP listeners for lockd.
212	222	*
213	223
214	224
...	...	@@ -222,13 +232,15 @@
222	232	static int warned;
223	233	int err;
224	234
225		- err = create_lockd_listener(serv, "udp", nlm_udpport);
	235	+ err = create_lockd_family(serv, PF_INET);
226	236	if (err < 0)
227	237	goto out_err;
228	238
229		- err = create_lockd_listener(serv, "tcp", nlm_tcpport);
230		- if (err < 0)
	239	+#if defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE)
	240	+ err = create_lockd_family(serv, PF_INET6);
	241	+ if (err < 0 && err != -EAFNOSUPPORT)
231	242	goto out_err;
	243	+#endif /* CONFIG_IPV6 \|\| CONFIG_IPV6_MODULE */
232	244
233	245	warned = 0;
234	246	return 0;